Detector Calibration - Agilent Technologies 1220 Infinity II LC User Manual

9
Test Functions and Calibration
Variable Wavelength Detector (VWD)

Detector Calibration

Wavelength Verification/Calibration
Wavelength Calibration of the detector is done using the zero-order position and
656 nm (alpha-emission line) and beta-emission line at 486 nm emission-line
positions of the deuterium lamp. The calibration procedure involves three
steps. First the grating is calibrated on the zero-order position. The
stepper-motor step position where the zero-order maximum is detected is
stored in the detector. Next, the grating is calibrated against the deuterium
emission-line at 656 nm, and the motor position at which the maximum occurs
is stored in the detector. Finally, the grating is calibrated against the
deuterium emission-line at 486 nm, and the motor position at which the
maximum occurs is stored in the detector.
The wavelength verification/calibration takes about 2.5 min and is disabled within the first
N O T E
10 min after ignition of the lamp because initial drift may distort the measurement.
When the lamp is turned ON, the 656 nm emission line position of the
deuterium lamp is checked automatically.
When to Calibrate the Detector
The detector is calibrated at the factory, and under normal operating
conditions should not require recalibration. However, it is advisable to
recalibrate:
• after maintenance (flow cell or lamp),
• after repair of components in the optical unit,
• after exchange of the optical unit or VWM board,
• at a regular interval, at least once per year (for example, prior to an
• when chromatographic results indicate the detector may require
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Operational Qualification/Performance Verification procedure), and
recalibration.
1220 Infinity II LC System User Manual